CN103470560A - Crane and power hydraulic system thereof - Google Patents
Crane and power hydraulic system thereof Download PDFInfo
- Publication number
- CN103470560A CN103470560A CN2013104417917A CN201310441791A CN103470560A CN 103470560 A CN103470560 A CN 103470560A CN 2013104417917 A CN2013104417917 A CN 2013104417917A CN 201310441791 A CN201310441791 A CN 201310441791A CN 103470560 A CN103470560 A CN 103470560A
- Authority
- CN
- China
- Prior art keywords
- oil circuit
- relief valve
- oil
- communicated
- hydraulic system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Fluid-Pressure Circuits (AREA)
Abstract
The invention discloses a power hydraulic system for a crane. The system comprises a reversing valve, wherein an oil outlet of the reversing valve is communicated with a first oil line and a second oil line through a flow diversion and collecting valve, the first oil line and the second oil line are respectively communicated with oil supply cavities of two oil cylinders when the hydraulic system does lifting operation, a bidirectional overflow valve is connected between the first oil line and the second oil line, and when the pressure difference between the first oil line and the second oil line is greater than the set pressure of the bidirectional overflow valve, oil liquid in the first oil line or the second oil line whichever has larger pressure flows into the first oil line or the second oil line whichever has smaller pressure. By adopting the structure, the bidirectional overflow valve can realize the pressure compensation between the first oil line and the second oil line, so the overlarge pressure difference is avoided. The hydraulic system has the advantages that on the basis of the flow diversion and collecting valve, the effect on the speed synchronous precision by the hydraulic power is reduced or eliminated, and the problem of bending deformation of a piston rod caused by overlarge pressure difference of the two oil cylinders is avoided.
Description
Technical field
The present invention relates to technical field of engineering machinery, relate in particular to a kind of hoist and dynamic hydraulic system thereof.
Background technique
Construction along with projects such as wind-powered electricity generation, chemical industry, high ferro, bridges, more and more need super-tonnage crane, and super-tonnage crane has the characteristics such as the lift heavy amount is large, the operating mode combination is many, the amplitude that hoists is high, operating range is large.Continuous increase along with the hoist tonnage, the balance weight that hoist needs also constantly increases, therefore need in hydraulic system, be set up in parallel two identical oil hydraulic cylinders simultaneously, drive two hydraulic cylinder synchronous actions during work, in order to provide enough lifting power for hoist.
Please refer to Fig. 1, the hydraulic schematic diagram that Fig. 1 is prior art medium power hydraulic system; Below briefly introduce the working principle of this hydraulic system and the technological deficiency of existence thereof.
As shown in Figure 1, this hydraulic system comprises two oil cylinders 1 and selector valve (not shown), the oil outlet of selector valve is communicated with the first oil circuit L1, the second oil circuit L2 by flow divider-combiner 2, the first oil circuit L1 is communicated with the rod chamber of one in two oil cylinders 1, and the second oil circuit L2 is communicated with the rod chamber of two oil cylinder 1 another one.
Adopt this structure, when the load of two oil cylinders 1 is identical, flow divider-combiner 2 two-way liquid resistances are identical, and the flow of two oil circuit outputs also equates, can realize that the movement velocity of two oil cylinders 1 is synchronous.
But, when the load of two oil cylinders 1 is different, before the spool of selector valve does not move, the load of the first oil circuit L1 and the second oil circuit L2 is no longer equal, the flow that flow divider-combiner 2 is distributed to the first oil circuit L1, the second oil circuit L2 is no longer identical.Although common flow divider-combiner 2 can be by the regulating spool position, realize that the first oil circuit L1 and the resistance of the second oil circuit L2 liquid equate as far as possible, but due to the shunting precision of flow divider-combiner 2 poor (being generally 3%), increase along with load hydraulic pressure deviation, it is poorer that shunting precision becomes gradually, therefore the pressure difference between the first oil circuit L1 and the second oil circuit L2 also increases gradually, when the pressure difference of the two increases to certain value, can produce unbalanced force radially to oil hydraulic cylinder, cause the phenomenons such as piston rod bending.More serious, above-mentioned wild effect also can cause serious accident, directly threatens operator's personal safety.Therefore, how thoroughly solving the nonsynchronous problem of twin-tub is the important problem that each hydraulic pressure designer faces.
In view of this, urgently for above-mentioned technical problem, hydraulic system of the prior art is done to further optimal design, to guarantee two hydraulic cylinder synchronous actions, avoid two oil cylinders because of problems such as the excessive generation piston rod of pressure reduction bendings.
Summary of the invention
Purpose of the present invention is for providing a kind of hoist and dynamic hydraulic system thereof, between two oil circuits of this system, bidirectional relief valve is set, to realize two pressure compensations between oil circuit, improve the synchronization accuracy of two oil hydraulic cylinders, avoid the generation of the phenomenons such as piston rod bending.
For solving the problems of the technologies described above, the invention provides a kind of dynamic hydraulic system for hoist, comprise selector valve and two oil cylinders, the oil outlet of described selector valve is communicated with the first oil circuit, the second oil circuit by flow divider-combiner, and when described the first oil circuit, described the second oil circuit promote operation with described hydraulic system respectively, the fuel supply chamber of two oil cylinders is communicated with; Be connected with bidirectional relief valve between described the first oil circuit and described the second oil circuit, so that the pressure difference between described the first oil circuit and the second oil circuit is while being greater than the set pressure of described bidirectional relief valve, described the first oil circuit, described the second oil circuit in the two the fluid of pressure the grater to the pressure smaller, flow.
Preferably, described bidirectional relief valve is split-type structural, comprise the first relief valve and the second relief valve, the filler opening of described the first relief valve is communicated with described the first oil circuit, oil outlet is communicated with described the second oil circuit, the filler opening of described the second relief valve is communicated with described the second oil circuit, oil outlet is communicated with described the first oil circuit, and described the first relief valve is identical with the set pressure of the second relief valve.
Preferably, described bidirectional relief valve is monolithic construction, comprise the first relief valve piece and the second relief valve piece, the filler opening of described the first relief valve piece is communicated with described the first oil circuit, oil outlet is communicated with described the second oil circuit, and its control port is communicated with filler opening; The filler opening of described the second relief valve piece is communicated with described the second oil circuit, oil outlet is communicated with described the first oil circuit, and its control port is communicated with filler opening; Described the first relief valve piece is identical with the set pressure of the second relief valve piece; Be connected with the two shared pressure spring between described the first relief valve piece and the second relief valve piece, in order to control the openings of sizes of described the first relief valve piece and the second relief valve piece.
Preferably, described the first oil circuit by the first equilibrium valve during with described hydraulic system lifting operation the fuel supply chamber of the one in two oil cylinders be communicated with.
Preferably, described the second oil circuit by the second equilibrium valve during with described hydraulic system lifting operation the fuel supply chamber of the another one in two oil cylinders be communicated with.
The invention provides a kind of dynamic hydraulic system for hoist, be connected with bidirectional relief valve between its first oil circuit and the second oil circuit, so that the pressure difference between the first oil circuit and the second oil circuit is while being greater than the set pressure of bidirectional relief valve, the first oil circuit, the second oil circuit in the two the fluid of pressure the grater to the pressure smaller, flow.
Adopt this structure, bidirectional relief valve can be realized the pressure compensation between the first oil circuit, the second oil circuit, avoid the two pressure reduction excessive, therefore, the invention provides hydraulic system and reduced or eliminated the impact of hydraulic power on the speed synchronization accuracy on the basis of flow divider-combiner, can avoid two oil cylinders to produce the diastrophic problem of piston rod because pressure reduction is excessive.
In a kind of embodiment, above-mentioned bidirectional relief valve is split-type structural, comprise the first relief valve and the second relief valve, the filler opening of described the first relief valve is communicated with described the first oil circuit, oil outlet is communicated with described the second oil circuit, and its control port is communicated with filler opening; The filler opening of described the second relief valve is communicated with described the second oil circuit, oil outlet is communicated with described the first oil circuit, and its control port is communicated with filler opening; Described the first relief valve is identical with the set pressure of the second relief valve.
Adopt this structure, when the pressure of the first oil circuit is greater than the pressure of the second oil circuit, and pressure difference is greater than set pressure, and the fluid of the first oil circuit flows to the second oil circuit by the first relief valve, and the pressure compensation of the first oil circuit is given the second oil circuit; The pressure and the pressure difference that are greater than the first oil circuit when the pressure of the second oil circuit are greater than set pressure, and the fluid of the second oil circuit flows to the first oil circuit by the second relief valve, and the pressure compensation of the second oil circuit is given the first oil circuit.As can be seen here, above-mentioned split type bidirectional relief valve simple in structure, can realize above-mentioned pressure compensation process easily.
The present invention also provides a kind of hoist, comprises balance weight mechanism and dynamic hydraulic system, and two oil cylinders of described dynamic hydraulic system are connected with described balance weight mechanism; Described dynamic hydraulic system adopts structure as above.
Because above-mentioned dynamic hydraulic system has as above technique effect, therefore, comprise that the hoist of this dynamic hydraulic system also should have identical technique effect, do not repeat them here.
The accompanying drawing explanation
The hydraulic schematic diagram that Fig. 1 is prior art medium power hydraulic system;
The hydraulic schematic diagram of a kind of embodiment that Fig. 2 is dynamic hydraulic system provided by the present invention;
Hydraulic schematic diagram in the another kind of embodiment that Fig. 3 is dynamic hydraulic system provided by the present invention.
Wherein, the reference character in Fig. 1 to Fig. 3 and the corresponding relation between component names are:
Oil cylinder 1;
Flow divider-combiner 2;
The first oil circuit L1; The second oil circuit L2;
Bidirectional relief valve 3; The first relief valve 31; The second relief valve 32; The first relief valve piece 31 '; The second relief valve piece 32 '; Pressure spring 33 ';
The first equilibrium valve 41; The second equilibrium valve 42.
Embodiment
Core of the present invention is for providing a kind of hoist and dynamic hydraulic system thereof, between two oil circuits of this system, bidirectional relief valve is set, can realize two pressure compensations between oil circuit, improve the synchronization accuracy of two oil hydraulic cylinders, thereby avoid the generation of the phenomenons such as piston rod bending.
In order to make those skilled in the art understand better technological scheme of the present invention, below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.
Please refer to Fig. 2, the hydraulic schematic diagram of a kind of embodiment that Fig. 2 is dynamic hydraulic system provided by the present invention.
In a kind of embodiment, as shown in Figure 2, the invention provides a kind of dynamic hydraulic system for hoist, this dynamic hydraulic system comprises selector valve and two oil cylinders 1, the oil outlet of selector valve is communicated with the first oil circuit L1, the second oil circuit L2 by flow divider-combiner 2, and when the first oil circuit L1, the second oil circuit L2 promote operation with hydraulic system respectively, the fuel supply chamber of two oil cylinders 1 is communicated with.Be connected with bidirectional relief valve 3 between the first oil circuit L1 and the second oil circuit L2.
Adopt this structure, preset the set pressure value of bidirectional relief valve 3, in working procedure, when the pressure difference between the first oil circuit L1 and the second oil circuit L2 is greater than the set pressure of bidirectional relief valve 3, the fluid of the first oil circuit L1, the second oil circuit L2 pressure the grater in the two flows to the pressure smaller, to reduce the pressure difference of the first oil circuit L1 and the second oil circuit L2.
As can be seen here, the bidirectional relief valve 3 of above-mentioned dynamic hydraulic system can be realized the pressure compensation between the first oil circuit L1, the second oil circuit L2, avoid the two pressure reduction excessive, therefore, the invention provides hydraulic system and reduced or eliminated the impact of hydraulic power on the speed synchronization accuracy on the basis of flow divider-combiner 2, can avoid two oil cylinders 1 to produce the diastrophic problem of piston rod because pressure reduction is excessive.
The concrete structure of above-mentioned bidirectional relief valve 3 can also further be set.
In a kind of concrete scheme, above-mentioned bidirectional relief valve 3 is split-type structural, the filler opening that comprises the first relief valve 31 and the second relief valve 32, the first relief valves 31 is communicated with the first oil circuit L1, oil outlet is communicated with the second oil circuit L2, and its control port is communicated with filler opening; The filler opening of the second relief valve 32 is communicated with the second oil circuit L2, oil outlet is communicated with the first oil circuit L1, and its control port is communicated with filler opening; The first relief valve 31 is identical with the set pressure of the second relief valve 32.
Adopt this structure, when the pressure of the first oil circuit L1 is greater than the pressure of the second oil circuit L2, and pressure difference is while being greater than set pressure, and the fluid of the first oil circuit L1 flows to the second oil circuit L2 by the first relief valve 31, and the pressure compensation of the first oil circuit L1 is given the second oil circuit L2; When the pressure of the second oil circuit L2 is greater than the pressure of the first oil circuit L1 and pressure difference and is greater than set pressure, the fluid of the second oil circuit L2 flows to the first oil circuit L1 by the second relief valve 32, and the pressure compensation of the second oil circuit L2 is given the first oil circuit L1.As can be seen here, above-mentioned split type bidirectional relief valve 3 simple in structure, can realize above-mentioned pressure compensation process easily.
As shown in Figure 3, the hydraulic schematic diagram in the another kind of embodiment that Fig. 3 is dynamic hydraulic system provided by the present invention.
In another kind of concrete scheme, as shown in Figure 3, above-mentioned bidirectional relief valve 3 can also adopt monolithic construction.Bidirectional relief valve 3 is monolithic construction, comprise the first relief valve piece 31 ' and the second relief valve piece 32 ', the first relief valve piece 31 ' filler opening with the first oil circuit L1, be communicated with, oil outlet is communicated with the second oil circuit L2, and its control port is communicated with filler opening; The second relief valve piece 32 ' filler opening with the second oil circuit L2, be communicated with, oil outlet is communicated with the first oil circuit L1, and its control port is communicated with filler opening; The first relief valve piece 31 ' with the second relief valve piece 32 ' set pressure identical; The first relief valve piece 31 ' and the second relief valve piece 32 ' between be connected with the two shared pressure spring 33 ', so that control the first relief valve piece 31 ' and the second relief valve piece 32 ' openings of sizes.This bidirectional relief valve 3 has compact structure, level of integration is high, is convenient to the installation and removal of bidirectional relief valve 3.
In another kind of embodiment, as shown in Figures 2 and 3, the fuel supply chamber of above-mentioned the first oil circuit L1 one in two oil cylinders 1 during by the first equilibrium valve 41 and hydraulic system lifting operation is communicated with.
Adopt this structure, the first equilibrium valve 41 can keep the load of the oil cylinder 1 that is attached thereto constant when static, the phenomenon of falling suddenly when avoiding balance weight mechanism static.
Similarly in scheme, above-mentioned the second oil circuit L2 by the second equilibrium valve 42 during with hydraulic system lifting operation the fuel supply chamber of the another one in two oil cylinders 1 be communicated with.
In the same manner, the second equilibrium valve 42 also can keep the load of the oil cylinder 1 that is attached thereto constant when static, and the phenomenon of falling suddenly while avoiding equally balance weight mechanism static further guarantees the working stability of hydraulic system.
The present invention also provides a kind of hoist, comprises balance weight mechanism and dynamic hydraulic system, and two oil cylinders 1 of dynamic hydraulic system are connected with balance weight mechanism; Dynamic hydraulic system adopts structure as above.
Because above-mentioned hydraulic control system has technique effect as above, therefore, comprise that the hoist of this hydraulic control system also should have identical technique effect, do not repeat them here.
Above a kind of hoist provided by the present invention and dynamic hydraulic system thereof are described in detail.Applied specific case herein principle of the present invention and mode of execution are set forth, above embodiment's explanation is just for helping to understand method of the present invention and core concept thereof.It should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention, can also carry out some improvement and modification to the present invention, these improvement and modification also fall in the protection domain of the claims in the present invention.
Claims (6)
1. the dynamic hydraulic system for hoist, comprise selector valve and two oil cylinders (1), the oil outlet of described selector valve is communicated with the first oil circuit (L1), the second oil circuit (L2) by flow divider-combiner (2), and when described the first oil circuit (L1), described the second oil circuit (L2) promote operation with described hydraulic system respectively, the fuel supply chamber of two oil cylinders (1) is communicated with; It is characterized in that,
Be connected with bidirectional relief valve (3) between described the first oil circuit (L1) and described the second oil circuit (L2), so that the pressure difference between described the first oil circuit (L1) and the second oil circuit (L2) is while being greater than the set pressure of described bidirectional relief valve (3), described the first oil circuit (L1), described the second oil circuit (L2) in the two the fluid of pressure the grater to the pressure smaller, flow.
2. the dynamic hydraulic system for hoist according to claim 1, is characterized in that, described bidirectional relief valve (3) is split-type structural, comprises the first relief valve (31) and the second relief valve (32),
The filler opening of described the first relief valve (31) is communicated with described the first oil circuit (L1), oil outlet is communicated with described the second oil circuit (L2), and its control port is communicated with filler opening; The filler opening of described the second relief valve (32) is communicated with described the second oil circuit (L2), oil outlet is communicated with described the first oil circuit (L1), and its control port is communicated with filler opening; Described the first relief valve (31) is identical with the set pressure of the second relief valve (32).
3. the dynamic hydraulic system for hoist according to claim 1, is characterized in that, described bidirectional relief valve (3) is monolithic construction, comprises the first relief valve piece (31 ') and the second relief valve piece (32 ');
The filler opening of described the first relief valve piece (31 ') is communicated with described the first oil circuit (L1), oil outlet is communicated with described the second oil circuit (L2), and its control port is communicated with filler opening; The filler opening of described the second relief valve piece (32 ') is communicated with described the second oil circuit (L2), oil outlet is communicated with described the first oil circuit (L1), and its control port is communicated with filler opening; Described the first relief valve piece (31 ') is identical with the set pressure of the second relief valve piece (32 ');
Be connected with the two shared pressure spring (33 ') between described the first relief valve piece (31 ') and the second relief valve piece (32 '), in order to control the openings of sizes of described the first relief valve piece (31 ') and the second relief valve piece (32 ').
4. according to the described dynamic hydraulic system for hoist of claim 1-3 any one, it is characterized in that, the fuel supply chamber of one when described the first oil circuit (L1) promotes operation by the first equilibrium valve (41) with described hydraulic system in two oil cylinders (1) is communicated with.
5. the dynamic hydraulic system for hoist according to claim 4, is characterized in that, the fuel supply chamber of another one when described the second oil circuit (L2) promotes operation by the second equilibrium valve (42) with described hydraulic system in two oil cylinders (1) is communicated with.
6. a hoist, comprise balance weight mechanism and dynamic hydraulic system, and two oil cylinders (1) of described dynamic hydraulic system are connected with described balance weight mechanism; It is characterized in that, described dynamic hydraulic system adopts as the described structure of claim 1-5 any one.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013104417917A CN103470560A (en) | 2013-09-25 | 2013-09-25 | Crane and power hydraulic system thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013104417917A CN103470560A (en) | 2013-09-25 | 2013-09-25 | Crane and power hydraulic system thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103470560A true CN103470560A (en) | 2013-12-25 |
Family
ID=49795551
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2013104417917A Pending CN103470560A (en) | 2013-09-25 | 2013-09-25 | Crane and power hydraulic system thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103470560A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106499686A (en) * | 2015-09-04 | 2017-03-15 | 熵零股份有限公司 | Bidirectional pressure-release valve |
| CN110329486A (en) * | 2019-07-19 | 2019-10-15 | 中国商用飞机有限责任公司北京民用飞机技术研究中心 | A kind of braced wing airplane support rod discharge mechanism |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1306297A (en) * | 1970-04-09 | 1973-02-07 | ||
| JP2008298259A (en) * | 2007-06-04 | 2008-12-11 | Kobelco Contstruction Machinery Ltd | Driving device of clipping work machine and construction machine having the driving device |
| CN102588364A (en) * | 2012-02-23 | 2012-07-18 | 徐州重型机械有限公司 | Hydraulic synchronous independent control device, synchronous hydraulic system and crane |
| CN102628459A (en) * | 2012-04-12 | 2012-08-08 | 中联重科股份有限公司 | Multi-oil-cylinder synchronous control system and engineering vehicle |
| CN202381427U (en) * | 2011-12-14 | 2012-08-15 | 徐州重型机械有限公司 | Hydraulic oil cylinder synchronization control loop and crane using same |
| CN102756952A (en) * | 2012-06-28 | 2012-10-31 | 三一重工股份有限公司 | Hydraulic reel-pipe control system, continuous wall grab bucket and chambering drilling machine |
| CN102979772A (en) * | 2012-12-10 | 2013-03-20 | 徐州重型机械有限公司 | Oil cylinder locking device, double-cylinder hydraulic control system and lifting equipment |
| JP2013096462A (en) * | 2011-10-31 | 2013-05-20 | Maeda Seisakusho Co Ltd | Hydraulic driving circuit for actuator synchronous operation and flow dividing valve |
| CN203532374U (en) * | 2013-09-25 | 2014-04-09 | 徐州重型机械有限公司 | Crane and power hydraulic system thereof |
-
2013
- 2013-09-25 CN CN2013104417917A patent/CN103470560A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1306297A (en) * | 1970-04-09 | 1973-02-07 | ||
| JP2008298259A (en) * | 2007-06-04 | 2008-12-11 | Kobelco Contstruction Machinery Ltd | Driving device of clipping work machine and construction machine having the driving device |
| JP2013096462A (en) * | 2011-10-31 | 2013-05-20 | Maeda Seisakusho Co Ltd | Hydraulic driving circuit for actuator synchronous operation and flow dividing valve |
| CN202381427U (en) * | 2011-12-14 | 2012-08-15 | 徐州重型机械有限公司 | Hydraulic oil cylinder synchronization control loop and crane using same |
| CN102588364A (en) * | 2012-02-23 | 2012-07-18 | 徐州重型机械有限公司 | Hydraulic synchronous independent control device, synchronous hydraulic system and crane |
| CN102628459A (en) * | 2012-04-12 | 2012-08-08 | 中联重科股份有限公司 | Multi-oil-cylinder synchronous control system and engineering vehicle |
| CN102756952A (en) * | 2012-06-28 | 2012-10-31 | 三一重工股份有限公司 | Hydraulic reel-pipe control system, continuous wall grab bucket and chambering drilling machine |
| CN102979772A (en) * | 2012-12-10 | 2013-03-20 | 徐州重型机械有限公司 | Oil cylinder locking device, double-cylinder hydraulic control system and lifting equipment |
| CN203532374U (en) * | 2013-09-25 | 2014-04-09 | 徐州重型机械有限公司 | Crane and power hydraulic system thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106499686A (en) * | 2015-09-04 | 2017-03-15 | 熵零股份有限公司 | Bidirectional pressure-release valve |
| CN110329486A (en) * | 2019-07-19 | 2019-10-15 | 中国商用飞机有限责任公司北京民用飞机技术研究中心 | A kind of braced wing airplane support rod discharge mechanism |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Chapple | Principles of hydraulic systems design | |
| CN102155447B (en) | Rotating hydraulic system of crane and rotating buffer valve thereof | |
| CN103244496B (en) | Rotary control valve group, revolution hydraulic control system and hoist | |
| CN203532374U (en) | Crane and power hydraulic system thereof | |
| CN102887435B (en) | Hydraulic system for controlling amplitude variation of crane boom, control method and crane | |
| CN205101299U (en) | Numerical control hydraulic pressure sheet material tubulation make -up machine hydraulic system | |
| CN201436280U (en) | Multi-point synchronization hydraulic lifting system | |
| CN103912535B (en) | Luffing gravity declines crane load sensitivity multiple directional control valve | |
| CN102192206A (en) | Hydraulic dynamic synchronization control and position compensation system | |
| CN104019066A (en) | Hydraulic control system of ocean platform hoisting mechanism | |
| CN104925694A (en) | Hydraulic lifting platform system capable of achieving synchronous oil cylinder lifting | |
| CN103641023B (en) | The hydraulic control system of control cock and hoist brake, hoisting crane | |
| WO2013086882A1 (en) | Crane, and closed-type hoist negative power control system for use with crane | |
| CN104196806A (en) | Synchronizing circuit of flow distributing and collecting valve for two-column gantry lifter | |
| CN108397434A (en) | Rotary buffering valve, Hydraulic slewing system and engineering machinery | |
| CN103470560A (en) | Crane and power hydraulic system thereof | |
| CN201696376U (en) | Hydraulic pressure compensator | |
| CN202451485U (en) | Hydraulic synchronization independent control device, synchronous hydraulic system and crane | |
| CN2172364Y (en) | Pressure adaptation multi-way orientable valve | |
| CN202239424U (en) | Bidirectional force couple four corner leveling control system for slide block of forging machine | |
| CN102398866B (en) | Crane luffing control valve and crane luffing hydraulic system | |
| CN102515025A (en) | Superstructure rotary hydraulic control system and crane with same | |
| CN101592172A (en) | The electrically-controlled multifunctional compact type control valve group | |
| CN102588364B (en) | Hydraulic synchronous independent control device, synchronous hydraulic system and crane | |
| CN203948706U (en) | Load-transducing multi-way valve |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20131225 |
|
| RJ01 | Rejection of invention patent application after publication |